1. Measurement/Calculation Units of Measure

2. Metric System based on powers of ten, so it’s easy to convert between units. Remember: –KING HENRY DANCED BEFORE DAWN COUNTING MONEY –Or –KING HENRY DIED BY DRINKING CHOCOLATE MILK

3. Units MegakilohectodekaBASEdecicentimillimicro Mkhda(none)dcm  10 6 10 5 10 4 10 3 10 2 10 1 10 0 or 1 10 -1 10 -2 10 -3 10 -4 10 -5 10 -6

4. SI base units QuantityBase UnitSymbol Timeseconds Lengthmeterm Massgramg TemperatureKelvinK Amount of a substancemolemol

5. SI derived units QuantityDerived UnitSymbol Volume: various formulas, such as LxWxH cubic centimeters or milliliters liters cm 3 or mL L Density: mass divided by volume grams per milliliter or grams per cubic centimeter g/mL or g/cm 3 (derived units are calculated from base units)

6. How to use Kilo Hecto Deka BASE Deci Centi Milli Left Right

7. NOTE: 1 cm 3 IS EQUAL TO 1 mL!!! And a cc is the same as a cm 3

9. Measurement/Calculation Scientific Notation/Accuracy &Precision

10. Rules to putting into Sci Not Must have a whole number between 1- 9 If you move: –Decimal to Left…exponent is Positive –Decimal to Right...exponent is Negative

11. Examples.0032 15 300 000 1.53 X 10 7 3.2 X 10 -3

12. Examples 5.00 X 10 4 2.32 X10 -3 5.0000 50 000 2.3200.00232

13. Addition/Subtraction Make exponents the same by moving decimal place and changing exponent Then add/subtract and put in correct Sci Not OR Type into your calculator Change mode to Sci

14. Example 5.00 X 10 4 +.244 X 10 4 OR Type into your calculator  5.00 X 10 4 + 2.44 X 10 3 5.244X 10 4 5.00 EXP EE 4 + + 2.44 EXP EE 3 Enter

15. Multiplication/Division Multiplication –Multiply numbers –Add exponents Division –Divide numbers –Subtract exponents Then put back in correct scientific notation!

16. Example (5.44 × 10 7 g) ÷ (8.1 × 10 4 mol) = 5.44 EXP EE ÷ ÷ EXP EE ENTER EXE 78.1 4 = 671.6049383= 670 g/mol= 6.7 × 10 2 g/mol Type on your calculator: = 0.67 X 10 3 g/mol = 6.7 × 10 2 g/mol

17. Accuracy and Precision Accuracy: how close a measurement is to the true value (the “correct answer”) Precision: how close a value is to other values in that series

19. Are the following groups of measurements accurate, precise, both, or neither? 1) Given: true mass of sample of zinc is 14.5 g Measurements made: 13.2 g, 15.6 g, 17.9 g, 12.0 g 2)Given: true volume of sample of water is 33.3mL Measurements made: 22.4 mL, 22.2 mL, 22.4 mL, 22.3 mL 3) Given: true length of copper wire is 58.5 cm Measurements made: 58.4 cm, 58.5 cm, 58.5 cm, 58.4 cm

20. Qualitative: a descriptive measurement (quality); does not involve numbers Quantitative: a numerical measurement (quantity)

21. Appropriate Units for Measurement

22. Measurement/Calculation Significant Figures

23. Alternative Way Pacific (Present) Atlantic (Absent)

24. If the decimal is present, start on the Pacific side at the first nonzero digit and count it and all the digits to the right of it. If the decimal is absent, start on the Atlantic side at the first nonzero digit and count it and all the digits to the left of it. Pacific (Present) Atlantic (Absent)

25. Example: How many significant figures? 743.44 506 440 20405 0. 707 2.440 24 784.30 0.09

26. Adding/Subtracting Add/Subtract First The answer has only as many decimal places as the measurement having the least number of decimal places. Example 190.2 g 65.291 g 12.38 g 267.871 g 1 3 2 Answer should have 1 decimal place 267.9 g

27. Multiplication/Division The answer has only as many significant figures as the measurement with the least number of significant figures. Example 13.78 g 11.3 mL 4 3 = 1.219469 g/mL Answer should have 3 significant figures 1.22 g\ml Mult/Divide First

28. Example –15000 –2030.0 –0.0020 252252

29. Measurement/Calculation Density

30. Derived unit –g/mL or g/cm 3 Mass/Volume

31. D. Density An object has a volume of 825 cm 3 and a density of 13.6 g/cm 3. Find its mass. GIVEN: V = 825 cm 3 D = 13.6 g/cm 3 m = ? WORK : m = DV m = (13.6 g/cm 3 )(825cm 3 ) m = 11 220 g=11 200g

32. D. Density A liquid has a density of 0.87 g/mL. What volume is occupied by 25 g of the liquid? GIVEN: D = 0.87 g/mL V = ? m = 25 g WORK : V = m D V = 25 g 0.87 g/mL V = 28.74mL = 29 mL

33. D. Density 1.A marble has a mass of 5.6 g. It is placed in a graduated cylinder with 50.0 mL of water. The water level rises to 53.4 mL. What is the density of the marble? GIVEN: D = ? V = 53.4-50 = 3.4 mL m = 5.6 g WORK : D = m V D = 5.6 g 3.4 mL D=1.647 g/mL = 1.6 g/mL 3.4 mL

34. Graphing Graphing is an important tool for expressing data so that it is easier to read and interpret Rules for graphing: --place the manipulated/independent variable (the one that was changed) on the x axis. --place the dependent/responding variable (the results of that change) on the y axis. (dry mix) DRY MIX y scale = largest y value – smallest y valuex scale = largest x value – smallest x value # of lines on the y axis# of lines on the x axis The graph should cover at least ¾ of the grid